1. Field of the Invention
The present invention relates to fluoropolymers and, in particular, relates to fluoropolymer compositions having improved properties, such as coatings of the type that are applied to flexible substrates, such as glasscloth, in which a non-stick surface and/or abrasion resistant surface is desired. In particular, the present invention relates to a fluoropolymer compositions that may be used to form coatings having improved non-stick or release characteristics and/or improved abrasion resistance, and to form films and blended powder compositions.
2. Description of the Related Art
Fluoropolymers are long-chain polymers comprising mainly ethylenic linear repeating units in which some or all of the hydrogen atoms are replaced with fluorine. Examples include polytetrafluoroethylene (PTFE), methylfluoroalkoxy (MFA), fluoro ethylene propylene (FEP), perfluoroalkoxy (PFA), poly(chlorotrifluoroethylene) and poly(vinylfluoride).
Glasscloth is one example of a flexible substrate that may be coated with a fluoropolymer coating. The coating typically includes a high molecular weight polytetrafluoroethylene (HPTFE), either by itself or including small amounts of additional polymers and/or fillers. One coating technique involves feeding a glasscloth web through a dip tank containing a dispersion of the fluoropolymer, and then feeding the coated web upwardly through a drying and sintering oven tower to cure or fix the coating. This process is usually repeated a number of times whereby up to 10 or more coating layers may be applied.
What is needed is improved fluoropolymer compositions for applications such as coatings for flexible substrates, such as glasscloth, that demonstrate improved abrasion resistance and/or release characteristics, and for use in other applications.